7,121 research outputs found
Description of a new species of Sitana Cuvier, 1829 from southern India
No full textDeepak, V., Khandekar, Akshay, Varma, Sandeep, Chaitanya, R. (2016): Description of a new species of Sitana Cuvier, 1829 from southern India. Zootaxa 4139 (2): 167-182, DOI: http://doi.org/10.11646/zootaxa.4139.2.
Incompressibility of H-Free Edge Modification Problems: Towards a Dichotomy
No full textGiven a graph G and an integer k, the H-free Edge Editing problem is to find whether there exist at most k pairs of vertices in G such that changing the adjacency of the pairs in G results in a graph without any induced copy of H. The existence of polynomial kernels for H-free Edge Editing (that is, whether it is possible to reduce the size of the instance to k^O(1) in polynomial time) received significant attention in the parameterized complexity literature. Nontrivial polynomial kernels are known to exist for some graphs H with at most 4 vertices (e.g., path on 3 or 4 vertices, diamond, paw), but starting from 5 vertices, polynomial kernels are known only if H is either complete or empty. This suggests the conjecture that there is no other H with at least 5 vertices were H-free Edge Editing admits a polynomial kernel. Towards this goal, we obtain a set ℋ of nine 5-vertex graphs such that if for every H ∈ ℋ, H-free Edge Editing is incompressible and the complexity assumption NP ⊈ coNP/poly holds, then H-free Edge Editing is incompressible for every graph H with at least five vertices that is neither complete nor empty. That is, proving incompressibility for these nine graphs would give a complete classification of the kernelization complexity of H-free Edge Editing for every H with at least 5 vertices.
We obtain similar result also for H-free Edge Deletion. Here the picture is more complicated due to the existence of another infinite family of graphs H where the problem is trivial (graphs with exactly one edge). We obtain a larger set ℋ of nineteen graphs whose incompressibility would give a complete classification of the kernelization complexity of H-free Edge Deletion for every graph H with at least 5 vertices. Analogous results follow also for the H-free Edge Completion problem by simple complementation
Parameterized Lower Bound and Improved Kernel for Diamond-free Edge Deletion
No full textA diamond is a graph obtained by removing an edge from a complete graph on four vertices. A graph is diamond-free if it does not contain an induced diamond. The Diamond-free Edge Deletion problem asks to find whether there exist at most k edges in the input graph whose deletion results in a diamond-free graph. The problem was proved to be NP-complete and a polynomial kernel of O(k^4) vertices was found by Fellows et. al. (Discrete Optimization, 2011). In this paper, we give an improved kernel of O(k^3) vertices for Diamond-free Edge Deletion. We give an alternative proof of the NP-completeness of the problem and observe that it cannot be solved in time 2^{o(k)} * n^{O(1)}, unless the Exponential Time Hypothesis fails
Rainbow Coloring Hardness via Low Sensitivity Polymorphisms
No full textA k-uniform hypergraph is said to be r-rainbow colorable if there is an r-coloring of its vertices such that every hyperedge intersects all r color classes. Given as input such a hypergraph, finding a r-rainbow coloring of it is NP-hard for all k >= 3 and r >= 2. Therefore, one settles for finding a rainbow coloring with fewer colors (which is an easier task). When r=k (the maximum possible value), i.e., the hypergraph is k-partite, one can efficiently 2-rainbow color the hypergraph, i.e., 2-color its vertices so that there are no monochromatic edges. In this work we consider the next smaller value of r=k-1, and prove that in this case it is NP-hard to rainbow color the hypergraph with q := ceil[(k-2)/2] colors. In particular, for k <=6, it is NP-hard to 2-color (k-1)-rainbow colorable k-uniform hypergraphs.
Our proof follows the algebraic approach to promise constraint satisfaction problems. It proceeds by characterizing the polymorphisms associated with the approximate rainbow coloring problem, which are rainbow colorings of some product hypergraphs on vertex set [r]^n. We prove that any such polymorphism f: [r]^n -> [q] must be C-fixing, i.e., there is a small subset S of C coordinates and a setting a in [q]^S such that fixing x_{|S} = a determines the value of f(x). The key step in our proof is bounding the sensitivity of certain rainbow colorings, thereby arguing that they must be juntas. Armed with the C-fixing characterization, our NP-hardness is obtained via a reduction from smooth Label Cover
sj-docx-1-jop-10.1177_02698811221131989 – Supplemental material for Belief changes associated with psychedelic use
No full textSupplemental material, sj-docx-1-jop-10.1177_02698811221131989 for Belief changes associated with psychedelic use by Sandeep M. Nayak, Manvir Singh, David B. Yaden and Roland R. Griffiths in Journal of Psychopharmacology</p
sj-docx-2-jop-10.1177_02698811221131989 – Supplemental material for Belief changes associated with psychedelic use
No full textSupplemental material, sj-docx-2-jop-10.1177_02698811221131989 for Belief changes associated with psychedelic use by Sandeep M. Nayak, Manvir Singh, David B. Yaden and Roland R. Griffiths in Journal of Psychopharmacology</p
Proceedings of ASME Turbo Expo 2013: Power for Land, Sea and Air, Volume 1A: Combustion, Fuels and Emissions
No full textShahrokh Etemad (with Sandeep Alavandi and Benjamin Baird) is a contributing author, Fuel Flexible Rich Catalytic Lean Burn System for Low Btu Fuels
FIGURE 2 in Description of a new species of Sitana Cuvier, 1829 from southern India
No full textFIGURE 2. Maximum likelihood tree with highest likelihood score based on the concatenated dataset. Bootstrap support is shown at each node. Numbers in parentheses refer to location ID in Table 1.Published as part of Deepak, V., Khandekar, Akshay, Varma, Sandeep & Chaitanya, R., 2016, Description of a new species of Sitana Cuvier, 1829 from southern India, pp. 167-182 in Zootaxa 4139 (2) on page 171, DOI: 10.11646/zootaxa.4139.2.2, http://zenodo.org/record/26133
FIGURE 3 in Description of a new species of Sitana Cuvier, 1829 from southern India
No full textFIGURE 3. Bayesian tree based on the concatenated dataset. Posterior probability shown at each node. Numbers in parentheses refer to location ID in Table 1.Published as part of Deepak, V., Khandekar, Akshay, Varma, Sandeep & Chaitanya, R., 2016, Description of a new species of Sitana Cuvier, 1829 from southern India, pp. 167-182 in Zootaxa 4139 (2) on page 173, DOI: 10.11646/zootaxa.4139.2.2, http://zenodo.org/record/26133
sj-docx-1-pie-10.1177_09544089221105938 - Supplemental material for Effect of nanospray on hydrodynamic cylindrical film flow of Sutterby–Casson nanoliquids: A renewable energy application
No full textSupplemental material, sj-docx-1-pie-10.1177_09544089221105938 for Effect of nanospray on hydrodynamic cylindrical film flow of Sutterby–Casson nanoliquids: A renewable energy application by Vasudeva Reddy Minnam Reddy, A Sreevallabha Reddy, R Suresh Babu and N Sandeep in Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering</p
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